Mythcutprojectx
Note: The correct title of this article is mythcutprojectx. It appears incorrectly here due to technical restrictions.
Author | John Pilkington |
Description | Script to preprocess MPEG-2 recordings from DVB-T before running MythArchive |
Supports |
As stated in the preamble, this script is essentially a replacement for the 'lossless' mythtranscode with cutlist for mpeg-2 recordings known to the mythtv database. Mythtranscode works well with many recordings, but it has problems with others, maybe because individual data streams start or stop. One typical failure mode reports that 'one buffer is full and the other is empty', and aborts, but other defects in the input may not be detected until they cause a failure in a later process such as DVD creation or a defect in the DVD that has been created. It seems that Project-X is more tolerant of defects in its input, and recordings preprocessed by this script usually yield good DVDs.
MythArchive does itself offer the ability to use Project-X to apply the MythTV cutlist. I have preferred to use this script. Applying the cutlist via Project-X within MythArchive? sometimes gave me the wrong sound channel, and it means that the size of the final file is not known when the recordings are selected. I also believe that the conversion and application of the cutlist here is more robust than in mythburn.py.
This script tells the user what PIDs are present and requires him/her to specify two: one video, one audio. The cutlist is not applied with single-frame accuracy but I have found it robust and 'good enough'. I have had very few failures when the script has been used on the original recording; it seemed less reliable when used on recordings that had been preprocessed using mencoder.
The script assumes that the recording will be in one of two folders that must be defined by editing, and uses two other folders for temp storage. The intention is to read from one disc and write to another, but this isn't essential. I hope that modifications for a different number of discs will be obvious.
At the time of writing 'commflag --clearcutlist' produces a stream of false error messages after completion.
The script (still called mythcutprojectx) uses ideas from scripts found in the mythtv lists: mythcutprojectx and pxcut.sh
#!/bin/sh -e # Copyright (C) 2010 John Pilkington # Largely based on scripts posted by Tino Keitel and Kees Cook in the Mythtv lists. # Usage: ./mythcutprojectx <recording> # <recording> is an mpeg2 file recorded by MythTV with a valid DB entry. # This script is essentially a replacement for the 'lossless' mpeg2 mythtranscode. # It will pass the recording and the MythTV cutlist to ProjectX. # If the cutlist is empty the entire recording will be processed. # It uses ffmpeg to report what streams are present and # asks the user to input the PIDs of the video and one audio stream. # It uses ProjectX to demux and mplex (from mjpegtools) to remux. # Output format is DVD compliant without nav packets. # It then clears the cutlist, updates the filesize in the database and rebuilds the seek table. # The result is apparently acceptable as a recording within MythTV and as input to MythArchive. # The ProjectX log file is kept. Other tempfiles are deleted. # The script needs to be edited to define some local variables. #################### # Variables RECDIR1, RECDIR2, TEMPDIR1, TEMPDIR2, PROJECTX, PASSWD need to be customised. # RECDIR1 and TEMPDIR1 should if possible be on different drive spindles. Likewise RECDIR2 and TEMPDIR2. RECDIR1=/mnt/f10store/myth/reca TEMPDIR1=/mnt/sam1/tempb RECDIR2=/mnt/sam1/recb TEMPDIR2=/mnt/f10store/myth/tempa #PROJECTX=/path/to/ProjectX.jar (or to a link to it) PROJECTX=~/projectx #PASSWD=`grep "^DBPassword" ~/.mythtv/mysql.txt | cut -d '=' -f 2-` PASSWD=mythtv ################# if test "$1" = "-h" || test "$1" = "--help" ; then echo "Usage: ./mythcutprojectx <recording>" echo "<recording> is an mpeg2 file recorded by MythTV with a valid DB entry." echo "e.g. 1234_20100405123400.mpg in one of the defined RECDIRs" echo "The output file replaces the input file which is renamed to <recording>.old" exit 0 fi # Customize with paths to alternative recording and temp folders cd $RECDIR1 TEMP=$TEMPDIR1 if [ ! -f "$1" ] ; then cd $RECDIR2 TEMP=$TEMPDIR2 if [ ! -f "$1" ] ; then echo " "$1" not found. Giving up" cd exit 1 fi fi if [ $# -lt 3 ] then echo "Error: needs three arguments. Running ffmpeg -i "$1" 2>&1 | grep -C 4 Video " echo ffmpeg -i "$1" 2>&1 | grep -C 4 Video echo echo "Expected Command Line is of the form ./mythcutprojectx 1234_20070927190000.mpg 0xvvv 0xaaa " echo " filename_in_DB vPID aPID " cd ~ exit 1 fi # chanid and starttime identify the recording in the DB chanid=`echo "select chanid from recorded where basename=\"$1\";" | mysql -N -u mythtv -p$PASSWD mythconverg ` starttime=`echo "select starttime from recorded where basename=\"$1\";" | mysql -N -u mythtv -p$PASSWD mythconverg ` # list0 gives start (cut-in) points but omits initial zero if start of recording is wanted; includes eof. list0=`echo "select mark from recordedmarkup where chanid=$chanid and starttime='$starttime' and type=0 order by mark;" | mysql -N -u mythtv -p$PASSWD mythconverg ` # list1 gives start of cut (cut-out points). Has initial zero if start of recording is to be cut list1=`echo "select mark from recordedmarkup where chanid=$chanid and starttime='$starttime' and type=1 order by mark;" | mysql -N -u mythtv -p$PASSWD mythconverg ` echo "CollectionPanel.CutMode=0" > cutlist$$ ; for i in $list1 ; do if [ $i = "0" ] then list=`echo "select mark from recordedmarkup where chanid=$chanid and starttime='$starttime' and type in (0,1) order by mark;" | mysql -N -u mythtv -p$PASSWD mythconverg | tail -n +2 ` # tail -n +2 drops the initial zero. else echo "0" >> cutlist$$ list=`echo "select mark from recordedmarkup where chanid=$chanid and starttime='$starttime' and type in (0,1) order by mark;" | mysql -N -u mythtv -p$PASSWD mythconverg ` fi # use only the first element of list1, as a switch. break done # find the key frame (mark type 9) right before each cut mark, # extract the byte offset, write it into the ProjectX cutlist for i in $list ; do echo "select offset from recordedseek where chanid=$chanid and starttime='$starttime' and type=9 and mark >= $i and mark < ($i + 100) order by offset;" | mysql -N -u mythtv -p$PASSWD mythconverg | head -n 1 # for each cycle, head -n 1 yields the first line only. done >> cutlist$$ echo "list0" echo $list0 echo echo "list1" echo $list1 echo echo "list" echo $list echo cat cutlist$$ echo #exit if [ -f "$1".old ] ; then echo " "$1".old exists. Giving up" exit 1 else mv "$1" "$1".old # use ProjectX to de-multiplex selected streams with the created cutlist ionice -c3 java -jar "$PROJECTX" -name tempcut$$ -id $2,$3 -out $TEMP -cut cutlist$$ "$1".old || : # and pipe for re-multiplexing to mplex. -f 9 is dvd format without navpacks ionice -c3 mplex -o "$1" -V -f 9 $TEMP/tempcut${$}.m2v $TEMP/tempcut${$}.mp2 # tell mythDB about new filesize and clear myth cutlist FILESIZE=`du -b "$1" | cut -f 1` if [ "${FILESIZE}" -gt 1000000 ]; then echo "running: update recorded set filesize=${FILESIZE} where basename=\"$1\";" echo "update recorded set filesize=${FILESIZE} where basename=\"$1\";" | mysql -u mythtv -p$PASSWD mythconverg echo "filesize has been reset" echo "running: ionice -c3 mythcommflag -f "$1" --clearcutlist" ionice -c3 mythcommflag -f "$1" --clearcutlist echo "cutlist has been cleared" fi #rebuild seek table echo "running: ionice -c3 mythtranscode --mpeg2 --buildindex --showprogress --chanid "$chanid" --starttime "$starttime"" ionice -c3 mythtranscode --mpeg2 --buildindex --showprogress --chanid "$chanid" --starttime "$starttime" echo "seek table has been rebuilt" echo "Output file is $1 - PID streams $2 and $3 copied" echo rm -f "$1".png #rm -f $TEMP/tempcut${$}* mv $TEMP/tempcut${$}_log.txt $TEMP/$1_pxlog.txt rm -f $TEMP/tempcut${$}.m2v rm -f $TEMP/tempcut${$}.mp2 rm -f cutlist$$ fi cd exit 0